Deflection equalizing means for shearing combs



Dec. 5, 1950 E. s. BARTLETT 2,532,476

DEFLECTION EQUALIZING MEANS FOR SHEARING vCOMBS Filed Aug. 16, 1948 WCMZW Patented Dec. 5, 1950 DEFLECTION EQUALIZING MEANS FOR SHEARING COMBSEdwin S. Bartlett, Forest Park, Ill., assigner to Sunbeam Corporation,Chicago, Ill., a corporation of Illinois Application August 16, 1948,Serial No. 44,566

6 Claims."

This invention relates to shearing handpieces and more particularly tomeans for providing a rigid support for a comb on such a handpiece.

It is customary for shearing handpiece manufacturers to make handpiecesin a plurality of sizes and capacities so that a user may have somechoice in the width of the comb and cutter of the handpiece. The reasonfor this is that some users require a handpiece having a relative- 1yWide comb Vand cutter and other users desire a handpiece having a narrowcomb and cutter. Too, in some countries the width of the comb and cutteris limited by statute. From experience it hasv been found that the samedriving mechanism may be utilized to drive the cutter mechanism whetherthe comb and cutter are narrow or relatively wide. In an efforttherefore to simplify manufacturing and to effect standardization ofparts of handpieces both the narrow combs and the relatively wide combshave been formed with mountinglslots or apertures of substantially thesame size spaced apart the same distance. Thus the same mounting screwscan be used to secure eithertype of comb to the handpiece. While thisstandardization of parts has been satisfactory from a manufacturingstandpoint it has not been entirely satisfactory from an operatorsorusers standpoint. Users have found that while a narrow comb, such as aten-tooth comb, is generally satisfactorily secured tothe handpiece withconventional mounting screws, that a relatively wide comb, such as athirteen-tooth comb, when mounted by the conventional mounting screws isnot satisfactorily secured to the handpiece. For example, as the cuttermoves between its lateral positions back and forth across the comb theextreme edge portions of the comb are displaced during the shearingoperation. This is believed to be due to the tension force applied tothe cutter to hold the latter` in engagement with the comb; that is thetensioning force is so great that it causes the edges of the comb to bedeflected away from the cutter, particularly during the shearingoperation, when the cutter is in either of its extreme lateralpositions. As a consequence, a good shearing action is not ,effected onthe edges of the comb of the handpiece. This of course is objectionablefrom the standpoint of reducing the efficiency of the user of thehandpiece.

Accordingly, it is an object of this invention to provide a novel meansfor securing a comb to thehandpiece which insures that the comb isreinforced along its lateral edges for preventing displacement thereofduring a shearing operation.

Another object of the invention is to provide means for securing thecomb to the handpiece 2 may be secured to the handpiece in a rigidlysupported manner throughout the entire area engaged by the cutter.

VAnother object of the invention is to provide novel means for securingcombs of different widths to the handpiece which permits themanufacturerY to standardize mounting hole dimensions on the combs,which is positive in its action, which is simple in construction, andwhich is relatively inexpensive to manufacture.

Other objects and advantages of the invention will become apparent fromthe following detailed description taken in connection with theaccompanying drawings, in which- Figure l is a side elevational view ofa shearing handpiece embodying the present invention;

Fig. 2 is a fragmentary bottom view of the handpiece shown in Figure l;

Fig. 3 is a sectional view taken substantially along the line 3-3 ofFig. 2 and showing the parts in a partially assembled position;

Fig. 4 is a sectional line taken substantially along the line 4-4 ofFig. 2 and showing the parts in a partially assembled position;

Fig. 5 is a bottom View of a cutter with a modiiied form of theinvention;

Fig. 6 is a sectional View taken Vsubstantially along the line 6-6 ofFig. 5;

Fig. 7 is a sectional view taken substantially along the line 'I-l' ofFig. 5, showing the part in an unassembled position, and v Fig. 8 is asectional view taken substantially along the line 8-8 of Fig. 5 showingthe part in an unassembled position. p

Referring now to the drawings, the invention is shown embodied in ashearing handpiece for shearing sheep and the like. In general, thehandpiece includes a handle portion H, a comb I2, a cutter I3, means l!!(of which only a portion is shown) for driving the cutter I3, andtensioning means i6 for adjusting the pressure between the cutter I3 andthe comb I2. As shown, the handle portion I! is of tubular constructionshaped `to be conveniently grasped by an operator. The comb I2 projectsoutwardly from the forward end of the handle portion Il as by having itsbase I'I secured on a shoulder I 8, formed on the underside of theforward end of the handle portion II, as by mounting screws I S. Thecutter I3 is mounted on top of the comb I2 and is arranged to be drivenback and forth across the comb by the driving means I4. Of the latter,only a yoke 2l drivingly interconnected with the cutter I3 and apivotally mounted fork 22 are shown. The yoke 2I is formed withdownwardly extending projections 23 shaped to be received in spacedrecesses (not shown) formed on the upper .surface of the cutter I 3. Atits rear end a shank 24 of the yoke 2I is received in a sleeve V25forming a part of the fork 22. The tensionof. tral portion of the plate3| is drawn against the ing means I6 includes a tension pin 26 havingone end seated in a bearing socket formed in a boss 21, integral withthe fork 22, and having its other end, not shown, extending through asleeve projection 28. The latter is integral with the forward end of thehandle portion Il and is inclined rearwardly of the front end of thehandle portion. The extreme end (not shown) of the tension pin 26 abutsagainst a cap 29 threadable on the sleeve projection 28, The pressurebetween the cutter I3 and the comb I2 may be adjusted by varying theposition of the cap 29 relative to the sleeve 28.

One phase of the invention is concerned with means for mounting the combI2 on the handle portion I I so that the combv is prevented from beingdisplaced relative to the handle portion I I during a shearingoperation. For this purpose, in the embodiment of the invention shown inFigs. l-4 a plate 3| is disposed between the heads of the mountingscrews I3 and the base I1 of the comb I2. As shown in Figs. 3 and 4 inwhich the parts are in a partially assembled position, that is thescrews I3 are not tightened up, the plate 3I has a concavo-convex crosssection in both a transverse and a longitudinal direction. The plate isof substantially the same thickness as the comb I2; has substantiallythe same overall width as the base i1 of the comb; and extends along thelongitudinal axis of the handpiece from the rearward edge of the base I1to a point adjacent the base of the teeth 32 of the comb I2. The plateis preferably formed of resilient material. With this construction theplate 3I in the partially assembled position, initially engages the combbase I1 at four positions defined by the corners 30 and 30' respectivelyof the plate. The forward corners 3i) of the plate 3l engage the combadjacent the base of the comb teeth 32 and adjacent the lateral edges ofthe base l1. rearward corners 39 of the plate 3I engage the base I1 ofthe comb I2 adjacent the rear edge of the base and adjacent the lateraledges there- When the screws I9 are tightened the cencomb. As aconsequence the marginal portions of the plate and particularly thecorner portions thereof are stressed to exert a pressure of greaterdegree against the comb. This distribution of pressure serves to preventthe comb from being equalize as well as minimize any tendency towarddeflection incident to cutter pressure. There is, of course, a smalldegree Vof deflection in the comb teeth due to their smallcross-section, but this is substantially uniform with the presentinvention.` Thus the plate 3I when in 'its assembled position provides apressure equalizing support as well as a reinforcement for the cor-nb.The forward edge of the plate 3I may be beveled as shown at V33 topermit the handpiece to be guided readily over the skin of the animal.The mounting holes in the plate 3l for the screws i9 are preferablycounterbored so that when the screws I9 arev in a tightened or securingposition the heads thereof do not interfere withv the free movement ofthe handpiece over the skin of an animal.

In the embodiment shown in Figs. 5-8 two generally Y-shaped or forkedmembers 35 and 35 formed from resilient material are utilized as a meansto. clamp. a comb 31 to a handpiece 3.4 to

The

prevent relative displacement of the comb with respect to the handpieceduring the shearing operation.

The Y-shaped member 35 includes a stem 38 and arm portions 39 and 4 I.The stem 38 as seen in Fig. 8 is formed with an aperture 42 having arounded bottom for receiving the correspondingly shaped head of amounting screw 43. At the extreme end of the stem 3B is a projection 44shaped to engage the lateral portion of the underside of the base 46 ofthe comb 31. On its arm portions 39 and 4I the Y-shaped member is formedwith projections 48 and 49, respectively, shaped to engage spacedpositions disposed centrally of the base 4B of the comb 31. The Y-shaped member 35 is of similar construction having a stem portion 5Iwith a central aperture 52 for receiving a mounting screw 43 and armportions 53 and 54. rThe stem and arm portions are provided withprojections 53, 51 and 58 respecf tively, shaped to engage the undersideof the base :36 of the comb 31 in a manner similar to that der scribedfor the Y-shaped member 35. As shown in Fig. 5 the arms of the Y-shapcdmember y35i overlap the arms of the Y-shaped member 35.

vFor this purpose the Y-shaped member 35 is formed with a recessedportion '59 on its top side which interiits with a similar recessedportion 6i on the underside of the Y-shaped member 35. As shown in Fig.6, when the screws 43 are in their securing position, the portion of thestems 33 and 5I adjacent the respective mounting holes is forced intoengagement with the -bottom of the comb. Because the portions of theY-shaped members 35 are bowed when the screws 43 are tightened it is tobe understood that stresses are set up in the members 35 and 3S toconstantly urge the projections into engagement with the comb. Thus,forces for holding the comb 31 in position are applied at lateralpositions on the base of the comb and at spaced positions at the centralportion of the base of the comb. Thus, this construction provides a combsecuring means in which the comb is positively reinforced by theapplication of equalized pressure at spaced points substantially alongthe full width of the comb.

It will be observed that in both embodiments pressure is applied alongsubstantially the full width of the comb by means of one or a multipleof clamping plates. This distributes the pressure at pre-determinedareas on the clamping plate spaced laterally from the clamping screwsI9. This distribution of the pressure has an equalizing effect whichserves to provide what might be termed a stabilized support for theclamping plate. This pressure distribution serves to effectively preventuneven deflection of the comb and particularly deflection oi the endportions of the cutter from the true plane in which its cutting edgesare designed to operate. These pressure equalizing and stabilizingeiiects function to promote a ner degree of precision in coactionbetween the cutting edges of the comb andthe cutter from end to end ofthe comb, withx the result that the shearing action is improved. Also,4the tendency toward dulling of the cutting edges due to comb deflectionsis reduced, with consequent improvement in the life of the comb andcutter.

The embodiments o f the invention shown herein are exceedingly simple inconstruction. Either construction permits of standardization or parts.Thus, either a narrow ten-tooth comb or a relatively wide thirteen-toothcomb provided.` with standard spacing Vbetween the mounting holes maybesecured to the, handle portion having con,

ventionally spaced mounting screws. As a result of the constructionsdisclosed herein a relatively wide comb may be secured to the handpiecell in a rigid manner without requiring a specially designed handpiece.VA

While I have shown two embodiments of my invention it will be understoodthat I do not wish to be limited thereto since many other modificationsmay be made and I therefore contemplate by the claims to cover suchmodications as fall within the true spirit and scope of my invention.

I claim:

1. In a shearing handpiece, the combination of a handle portion, a combprojecting outwardly from the handle portion and having a base portionseated thereon, a cutter movable back and forth across said comb betweenextreme lateral positions, tensioning means engageable with said cutterfor applying a pressure thereto to urge the cutter into engagement withthe comb, resilient plate means disposed adjacent the comb and shapedwhen initially assembled adjacent the comb to engage the latter at aplurality of spaced positions, two of said positions being adjacentopposite lateral edges of said comb, and means for securing the platemeans' to the comb and deforming said plate means to a position in whichthe portions thereof adjacent the securing means are in contiguousrelation with the comb, and said plate means is stressed to urge thelateral portions thereof into engagement with the lateral edges of thecomb to provide a support for the comb to positively retain the lateraledge portions in a fixed position as the/cutter moves between itslateral positions.

2. In a shearing handpiece, the combination of a handle, a combprojecting axially outwardly from the handle and having a base portionseated on said handle, a blade movable back and forth across said combbetween lateral positions, tensioning means engageable with the bladefor applying a pressure thereto to force the blade into engagement withthe comb, a plate movable between a position in which it has a surfacewhich is generally concave in both a transverse and a longitudinaldirection, and a position in which said surface is in contiguousrelation with the comb, said plate in the latter position being stressedto have its edge portions urged into engagement with the comb, abuttingagainst said base portion to provide a reinforced support for the combas the cutter moves between its lateral positions, and means forsecuring the plate in its last mentioned position.

3. In a shearing handpiece, the combination of a handle, a combprojecting outwardly from the handle and having a base portion seated onsaid handle, a 4blade movable back and forth across said comb betweenextreme lateral positions, tensioning means engageable with the bladefor applying a pressure thereto to urge the blade into engagement withthe comb throughout its path 'of travel, a first forked member havingprojections on each of its arm portions engageable with the base portionat spaced axial positions disposed centrally thereof and having aprojection on its stem portion engageablewith the base portion along onelateral edge thereof, a second forked member having projections on eachof its arm portions engageable with the base portion at spaced axialpositions disposed centrally thereof and having a projection on its stemportion engageable with the base portion on its other lateral edge, andmeans for securing thev forked members and the comb to the handle sothat the forked members are under stress and the projections areconstantly urged into engagement with the comb to provide areinforcement for the comb for preventing displacement thereof at eitherlateral edge or an intermediate position during the movement of thecutter between its extreme positions.

4. The combination recited in claim 3 in which the arm portions of thefirst forked member overlap the arm portions of the second forkedmember.

5. In a shearing hand piece, the combination of a handle, a combprojecting axially outwardly from the handle and having a base portionseated on said handle, a blade movable back and forth across said combbetween extreme lateral positions, tensioning means engageable With theblade for applying a pressure thereto to urge the blade into engagementwith the comb throughout its path of travel, a first forked memberhaving its arm portions shaped to engage spaced central positions of thebase portion and its stern portion shaped to engage one lateral edge ofthe base portion, a second forked member having its arm portions shapedto engage spaced central positions of the base portion and having itsstem portion shaped to engage the opposite lateral edge of the'baseportion, and means extending through each of said forked members forsecuring the forked members and the comb to the handle, said forkedmembers in their assembled positions providing a reinforcement for thecomb for preventing displacement thereof at either lateral edge or anintermediate position during the movement of the cutter between itsextreme positions.

6. In a shearing hand-piece having a head equippedwith a comb and acutter, the comb having a flat body portion and teeth extendingforwardly therefrom, means for oscillating the cutter, and tensioningmeans for applying pressure against the cutter to maintain it incoaction with the comb, the combination of a plate structure adapted tobe applied to the under side of the comb body portion, the platestructure having contact portions arranged to engage the under side ofthe comb body portion at points transversely spaced thereon and adjacentto the outer opposite edges thereof and having additional contactportions for engaging the under side of the comb body portion at pointslongitudinally spaced thereon, the plate structure intermediate saidcontact portions being spaced from the under side of the comb bodyportion when the plate structure is positioned on the comb body portion,and clamping means for applying pressure to said intermediate portion ofthe plate structure to thereby apply pressure through said Contactportions against the comb body portion at said transversely andlongitudinally spaced points.

EDWIN S. BARTLETT.

REFERENCES CITED The following references are of record in the iile ofthis patent:

UNITEDV STATES PATENTS Name Date Number Cook Jan. 30, 1917

